entitymanager

问题 I am new to EJB, creating an application for fun/learning EJB following is the code. @Entity @Table(name = "PERSON", schema = "experiment") @NamedQuery(name = "Person.fetchAllPerson" , query = "select p from Person p") public class Person implements Serializable { private static final long serialVersionUID = 1L; @Id @GeneratedValue(strategy = GenerationType.AUTO) @Column(name = "id") private Long id; @Column(name = "name", length = 500) private String name; @Column(name = "age") private

问题 I'm trying to get a better handle on the use of Spring's @Transactional attribute. I understand that it basically wraps the contents of the method marked as @Transactional in a transaction. Would it be appropriate to mark a service/business layer method as transactional, as opposed to the actual DAO method, as I have done here? Service Implementation public class UserServiceImpl implements UserServiceInt{ @Autowired private UserServiceDAO serviceDAO; @Override public User getUser(int id){

问题 I'm trying to get a better handle on the use of Spring's @Transactional attribute. I understand that it basically wraps the contents of the method marked as @Transactional in a transaction. Would it be appropriate to mark a service/business layer method as transactional, as opposed to the actual DAO method, as I have done here? Service Implementation public class UserServiceImpl implements UserServiceInt{ @Autowired private UserServiceDAO serviceDAO; @Override public User getUser(int id){

问题 I'm trying to get a better handle on the use of Spring's @Transactional attribute. I understand that it basically wraps the contents of the method marked as @Transactional in a transaction. Would it be appropriate to mark a service/business layer method as transactional, as opposed to the actual DAO method, as I have done here? Service Implementation public class UserServiceImpl implements UserServiceInt{ @Autowired private UserServiceDAO serviceDAO; @Override public User getUser(int id){

问题 I want to Execute the SQL , which will be constructed completely at runtime and it can be querying any tables in the schema. Something like @Repository public interface BaseRepository extends JpaRepository<Object, Integer> { @Query(":dynamicSQL") List<Object> dynamicExecution(@Param("dynamicSQL") String dynamicSQL); } Please suggest how this can be implemented 回答1: JpaRepository is not designed to be used like this. If you want to execute dynamic SQL query then use EntityManager. This is bad

问题 Need to retrieve latest data whose status is 1 and then setting status 0 for the same using LockMode Pessimistic . so Db column are => id(autogenerated), count, category_key, status(initially 1 for all). I have pre-populated data in db where for each category_key combination I have 10000 count.... so lets say for DG_KK I have 1 to 10000 count with status 1 and then for DG_TG I have 1 to 10000 count with status 1. Now Now I when I pass key DG_KK as category_key then from db using atomic fetch

问题 Noob question here. I'm following this example/tutorial to try and isolate a problem I keep getting on my main project. Problem is, the entityManagerFactory keeps returning null (thus, I get a NullPointerExcept when trying to run the first JUnit test.) I'm currently on Eclipse Indigo (JavaEE) - JRE7 - Hibernate 3.6.7 and JBoss 7 And here's my persistence.xml (again, a copipasta taken right from the tutorial) <persistence> <persistence-unit name="examplePersistenceUnit" transaction-type=

问题 Noob question here. I'm following this example/tutorial to try and isolate a problem I keep getting on my main project. Problem is, the entityManagerFactory keeps returning null (thus, I get a NullPointerExcept when trying to run the first JUnit test.) I'm currently on Eclipse Indigo (JavaEE) - JRE7 - Hibernate 3.6.7 and JBoss 7 And here's my persistence.xml (again, a copipasta taken right from the tutorial) <persistence> <persistence-unit name="examplePersistenceUnit" transaction-type=

问题 I'm trying to get the Hibernate's SessionFactory from JPA's EntityManager with the following lines: @PersistenceContext EntityManager manager; public SessionFactory getSessionFactory(){ sessionFactory = manager.unwrap(SessionFactory.class); } But it throws this exception: org.springframework.orm.jpa.JpaSystemException: Hibernate cannot unwrap interface org.hibernate.SessionFactory; nested exception is javax.persistence.PersistenceException: Hibernate cannot unwrap interface org.hibernate

问题 I'm trying to get the Hibernate's SessionFactory from JPA's EntityManager with the following lines: @PersistenceContext EntityManager manager; public SessionFactory getSessionFactory(){ sessionFactory = manager.unwrap(SessionFactory.class); } But it throws this exception: org.springframework.orm.jpa.JpaSystemException: Hibernate cannot unwrap interface org.hibernate.SessionFactory; nested exception is javax.persistence.PersistenceException: Hibernate cannot unwrap interface org.hibernate